1. Field of the Invention
The present invention relates to an ethanol marking ink composition, and more particularly, to an ethanol marking ink composition containing titanium oxide dispersed therein for a marking pen.
2. Description of the Related Art
Conventional quick-drying pigment inks for marking pens in which titanium oxide is dispersed contain an organic solvent harmful to man such as xylene and the like as a main solvent. When such a marking pen is actually used, man inevitably inhales the organic solvent harmful to man.
Therefore, it is desirable to use an ink comprising a less toxic and quick-drying organic solvent such as ethanol and the like as a main solvent. However, when ethanol is used as a main solvent, it is difficult to select a resin which can impart good fixability, weather resistance, and fastness to drawing lines and in which titanium oxide, a white coloring agent having a high hiding power, can be dispersed.
Among organic solvents, ethanol has a structure similar to water. Therefore, resins soluble in ethanol are also soluble in water.
On the other hand, xylene, a conventional main solvent, can dissolve a resin insoluble in water since xylene is an aromatic hydrocarbon, and therefore, xylene has been used for a long time in spite of the toxicity to man. The ink composition containing xylene is quick-drying and the drawing lines have excellent fixability, weather residence, and fastness, but there are disadvantages that when the pen is allowed to vertically stand, titanium oxide precipitates to form a hard cake and the titanium oxide thus precipitated can not be dispersed again by shaking the pen for stirring and moreover when the pen is allowed to stand still for a long period of time, writing becomes difficult.